Append or prepend different things to your form elements with input-group.
Make long content inside an input-group-addon overflow by wrapping your text with <span class="input-group-constrain"></span>.
input-group-addon
<span class="input-group-constrain"></span>
Chain several input-group-addon's or input-group-btn's together by adding the class input-group-insert to any input-group-addon or input-group-btn that sits between the first and last element inside an input-group.
input-group-btn
input-group-insert
An alternative style for input-group.